Root ID (8 bytes) (BPDU)

Protocol: BPDU (Spanning Tree) BPDU PCI

Field: root ID

Length: 8 bytes

Contents: root bridge ID.

Indicates the unique root bridge identifier. Each bridge is configured with a 2-octet priority value which is added to the 6-octet ID. The priority portion is the numerically most significant portion. The 8-octet root ID consists of the priority followed by the ID of the bridge that is the root.